From The Collaborative International Dictionary of English v.0.48:
Callot \Cal"lot\, n.
A plant coif or skullcap. Same as Calotte. --B. Jonson.
[1913 Webster]
From The Collaborative International Dictionary of English v.0.48:
Calotte \Ca*lotte"\, Callot \Cal"lot\, n. [F. calotte, dim. of
cale a sort of flat cap. Cf. Caul.]
A close cap without visor or brim. Especially:
(a) Such a cap, worn by English serjeants at law.
(b) Such a cap, worn by the French cavalry under their
helmets.
(c) Such a cap, worn by the clergy of the Roman Catholic
Church.
[1913 Webster]
To assume the calotte, to become a priest.
[1913 Webster]